CENTRAL PROCESSING UNIT (CPU)
The Central Processing Unit (CPU), sometimes simply referred to as the processor, is the brains of the computer and is a vital part of a computer system. This is where all the processing of data is carried out. The data processes are obtained from the main memory, via the system bus.
On large machines the CPU may require one or more circuit boards but in PCs and desktop computers it is housed in a single chip called a microprocessor.
Within the CPU you will find the Arithmetic Logic Unit (ALU), which performs arithmetic and logical operations, and the control unit, which loads, decodes and executes instructions and calls on the ALU when it is needed.
It is worth knowing that the CPU can only carry out simple arithmetic operations, comparisons between the results of a calculation and other values, and the selection of the next instruction for processing. All of the other seemingly limitless operations that a computer can perform are built on this very primitive base by low and high- level programming.
This is very important to someone working in the computer graphics field because without it there would be no computer. Also, the faster the CPU, the better it is for handling graphical computation.
The speed of the chip is primarily defined by the clock speed, but the number of transistors and the size of the address and data buses also play a part. The bigger the bus width, the more data can be transferred and the quicker the instructions requiring that data can be executed. Also, a greater number of transistors mean that there can be more pipelines to decode and execute the instructions. This in turn means that more instructions can be processed in less time. These increases have allowed processors today to run around 7,000 MIPS (millions of instructions per second.)